Tiberius rose to power in 574 when Justin II, prior to a mental breakdown, proclaimed him caesar and adopted him as his own son.

[11] While attempting to follow up that victory in late 570 or early 571, Tiberius was defeated in a battle in the Danube regions in which he narrowly escaped death, as his army was fleeing the battlefield.

[12] In 574, Justin had a mental breakdown, forcing Empress Sophia to turn to Tiberius to manage the empire, which was fighting the Persians to the east and dealing with the internal crisis of the plague.

[10] To achieve a measure of breathing space, Tiberius and Sophia agreed to a one-year truce with the Persians, at the cost of 45,000 solidi.

Tiberius also charted a very different course from his predecessor and proceeded to spend the money that Justin had doggedly saved in order to defend the imperial frontiers and win over the populace who had turned against him.

[17] John of Ephesus, a contemporary East Roman, wrote that Tiberius lavishly gave presents to "all men" and later as emperor, tended to give money away to the rich and did nothing for the poor.

[19] Alongside generous donations, he also proceeded to reduce state revenue by removing taxes on wine and bread instituted by Justinian I.

[20][21] Not content with making preparations, Tiberius also used this period to send reinforcements to Italy under the command of Baduarius with orders to stem the Lombard invasion.

[20] Tiberius was unable to respond as the Sassanid Emperor Khosrau I struck at the empire's Armenian provinces in 576, sacking Melitene and Sebastea.

Shifting his attention eastward, Tiberius sent his general Justinian with the eastern armies to push Khosrau and the Persians back across the Euphrates.

[14] Once Tiberius was elevated to the rank of Augustus, however, he had his family moved into the palace and renamed Ino as Anastasia, much to Sophia's resentment.

Therefore, Sophia sought revenge, and a secret pact was made between the dowager empress and general Justinian, whom Tiberius had replaced the year before.

[22] He formed an alliance with one of the Visigothic princes in Spain, who was fomenting rebellion, and his general Gennadius defeated the rebellious Berbers under their king Garmul in North Africa.

[5] Consequently, he might have been the basis for the fictional emperor Lucius Tiberius of Arthurian legend, who sent envoys to former Roman provinces after a long period without an imperial presence.

[26] At the same time, the Slavs began to migrate into Thrace, Macedonia and southern Greece, which Tiberius was unable to halt as the Persians refused to agree to a peace in the east, which remained the emperor's main priority.

[26] Although a new Persian invasion was halted with a significant defeat at Constantina in June 582, by now, Tiberius was dying, apparently having eaten some poorly prepared food.

[27][29] Tiberius died on the following day, 14 August 582, and his last words were spoken to his successor:[30] Let my sovereignty be delivered to thee with this girl.

[5] In the 18th century, Edward Gibbon assessed Tiberius II as a good emperor who benevolently distributed wealth to the population.